Recently, the degree of integration of electronic components (for example, IC and LSI) used in electronic equipment such as a computer has been increasing and accordingly, electronic equipment has been downsized and thinned. However, downsizing and thinning an electronic equipment reduces space inside the housing, and as a result, placing a cooling unit near the electronic component becomes difficult. Especially, an electronic component whose heat generation amount is high requires a larger cooling unit corresponding to the heat generation amount, which requires more space. Therefore, Patent Literatures 1 and 2 disclose a vapor phase cooling apparatus that utilizes a phase change of refrigerant to move heat to a different place where cooling is performed.
In the vapor phase cooling apparatus disclosed in Patent Literatures 1 and 2, an electronic component is disposed on a vertical surface of the vapor phase cooling apparatus. When the electronic component generates heat, the generated heat is conducted to the refrigerant, which, in turn, changes its phase from liquid to vapor (boils). When liquid refrigerant becomes vapor refrigerant, the vapor refrigerant moves upward while retaining heat, due to a difference in density from the surrounding liquid refrigerant. Above the electronic component is disposed a heat sink, and the resulting vapor refrigerant enters into the heat sink, where the vapor refrigerant changes its phase from vapor to liquid (condenses), thereby cooling the electronic component.